1. Field of the Invention
This invention relates to detergent compositions suitable for washing colored fabrics, and more particularly, to laundry detergent compositions containing a water soluble poly(4-vinylpyridine betaine) polymer as a dye transfer inhibitor (DTI) therein.
2. Description of the Prior Art
Dye complexing polymers have been used in laundry detergent and fabric softener compositions. However, during washing a mixture of colored and white fabrics, some of the dyes may bleed out of a colored fabric under washing conditions. The degree of bleeding is influenced by the structure of the dye, the type of cloth and the pH, temperature and mechanical efficiency of the agitation process. The bled dye in the wash liquor can be totally innocuous and get washed off in the wash liquor. However, in reality, this fugitive dye has a tendency to redeposit either onto the same fabric or onto another fabric leading to patches and an ugly appearance of the washed material. This redeposition of the bled dye can be inhibited in several ways. One method is to introduce a DTI compound which can complex with the fugitive dye and get washed off thus preventing redeposition.
Polyvinylpyrrolidone (PVP), by virtue of its dye complexation ability, has been used to inhibit dye deposition during washing of colored fabrics under laundry conditions. The performance of PVP as a DTI, however, is adversely affected by the presence of anionic surfactants in the washing process.
Other polymers which have been used as DTIs in laundry detergent compositions include polyvinylpyridine N-oxide (PVPNO); polyvinylimidazole (PVI); and copolymers of polyvinylpyridine and polyvinylimidazole (PVP-PVI).
The prior art in this field is represented by the following patents and publications:
______________________________________ Patent Subject Matter ______________________________________ (l) JP 53-50732 Formulas Nos. 3, 6 and (l) are water insoluble compounds and polymers used in printing ink compositions; (2) PCT/US94/06849 Dye inhibiting composition polymers WO 95/03390 of PVP, polyamine N-oxide, vinylimidazole are used in laundry detergent compositions; (3) USP 5,460,752 Polyamine N-oxide polymers described for use in laundry detergent compositions; (4) EPA 664335 A1 Polysulfoxide polymers; (5) PCT/US93/10542 Laundry compositions include WO 94/11473 polyamine-N-oxide and brighteners and surfactants; (6) PCT/EP93/02851 PVP and PVI are present in laundry WO 94/10281 compositions; (7) PCT/US94/11509 Poly (4-vinylpyridine-N-oxide) (PVPNO) WO 95/13354 and copolymers of VP and VI are described; (8) EP 754748 A1 Vinylpyridine copolymers and formic acid; (9) EP 0664332A1 Polyamine oxide polymers; (10) USP 5,604,197 PVPNO + clay softening; (11) USP 5,458,809 PVPNO; (12) USP 5,466,802 PVPNO and PVP-VI; (13) USP 5,627,151 Copolymers of VP or VI; vinylpyridine or dimethylaminoethyl methacrylate or dimethylaminopropylmethacrylamide, including up to 20% vinylacetate; (14) PCT/US95/04019 PVPNO, PVP, PVP-PI and copolymers of WO 95/27038 VP and VI; (15) EPA 628624 A1 PVPNO with protease; (16) DE 4224762 A1 VP polymers; (17) J. Polymer Water-insoluble poly(4-vinylpyridine) Sci. 26, compounds and polymers No. 113, p. 25-254 (1957) (18) W09723591 Anionic alkylbenzene sulfonate and non-ionic surfactants in detergent compositions containing PVP/PVI copolymers ______________________________________
Accordingly, it is an object of this invention to provide laundry detergent compositions including a water soluble dye transfer inhibitor (DTI) polymer which is a water soluble poly(4-vinylpyridine betaine) containing both a quaternary nitrogen and a carboxylate salt.
Another object of the invention is to provide such laundry detergent compositions suitable for washing colored fabrics alone or with white fabrics even in the presence of anionic surfactants.